An electroabsorption modulator (or electro-absorption modulator) is a semiconductor -based optical modulator. It can be used for controlling (modulating) the intensity (more precisely: the optical power) of a laser beam via an electric voltage (→ intensity modulators). The optical module serves as a crucial component in optical fiber communication systems, operating at the physical layer, which is the lowest layer in the OSI model. Its principle of operation is. T. 25-m CMOS Technology,” IEEE Journal of Solid-State Circuits, Mar.